IAC harness issue

[usar17]

So im gettig everything on this 350tbi set to factory when i realize the IAC isnt seating properly. I try a few different ones i had on hand and none were moving. So I grabbed my multimeter and tested the pins at the plug while the ALDL is grounded.

Battery with eng off = 10v
A- 11v
B- .3v
C- 11v
D- .3v

This right??? only thing ive found online is that B&C should be 12v and A&D should be .5v

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

 

[usar17]

Just switched the pins for A and B....still no response from the 3 IAC valves i tested. The one in the motor i know worked before this rebuild

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

 

[usar17]

Found my wiring diagram. Original way was correct. Switched it back, all wires tested for shorts and continuity, no problems. Plugged in another ECM i have, no change. Just grabbed a new IAC valve. Still nothing...wtf. with aldl pins a and b jumped it should be clicking and pushing the pital out correct???

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

 

[Georgeb]

Found my wiring diagram. Original way was correct. Switched it back, all wires tested for shorts and continuity, no problems. Plugged in another ECM i have, no change. Just grabbed a new IAC valve. Still nothing...wtf. with aldl pins a and b jumped it should be clicking and pushing the pital out correct???

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

yes, with the ignition switch on.

 

[usar17]

Nothing happens. But if.i start the engine normally i can watch it push out, then fly out when i turn the motor off lol

So i tested the aldl. Ground on A, 5v on B.

Any thoughts here???im stumped

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

 

[Georgeb]

when you jump A/B does the check engine light flash at least code 12?

 

[usar17]

Yup

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208

 

[Georgeb]

I would have to do some researching from here. Seems to me I came across this once. If I get time I will do a little digging. in the mean time perhaps others will chime in.

 

[bucket]

So it does operate when the engine is running (just not correctly)? And it doesn't operate for testing? Right?

What problem are you having that made you look into it in the first place?

 

[usar17]

Just did a rebuild. Wanted to set min idle. It seems to reset to full extension every ine i turn the truck off. Wo i turned it off, unplugged, and restarted to set idle. Just weird that the aldl jumping didnt work

-Shawn
1985 Chevy k10 w/ 92 TBI, 94 4l60e, 91 NP208